Rumoer 63: Extreme Forces| BouT | TU Delft by RuMoer

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63. Extreme Forces

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Extreme Forces

RUMOER 63 4st Quarter 2016 22nd year of publication Praktijkvereniging BouT Room 02.West.090 Faculty of Architecture, TU Delft Julianalaan 134 2628 BL Delft The Netherlands tel: +31 (0)15 278 1292 fax: +31 (0)15 278 4178 www.PraktijkverenigingBouT.nl rumoer@PraktijkverenigingBouT.nl Printing Drukkerij Teeuwen, Capelle aan den IJssel ISSN number 1567-7699 Credits Edited by:

Popi Papangelopoulou

Article editing:

Popi Papangelopoulou Allard Huitema Marc Nicolai Layla A van Ellen Antigoni Lampadiari-Matsa

Cover design: Cover image:

Popi Papangelopoulou NYC Apple store glass floor, Eckersley O’Callaghan

RUMOER is a periodical of Praktijkvereniging BouT, student and practice association for Building Technology (AE+T), at the Faculty of Architecture, TU Delft (Delft University of Technology). This magazine is spread among members and relations.

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-Extreme ForcesThe RUMOER committee is open to all students. Are you a creative student that wants to learn more about editing and illustrations? Come join us on our weekly meeting or email us: rumoer@praktijkverenigingbout.nl Circulation: The RUMOER appears 3 times a year, with 100 printed copies circulation and digital copies made available to members through online distribution. Membership Amounts per academic year (subject to change): € 10,Students € 30,PhD Students and alumni € 30,Academic Staff Single copies

Available at Bow Shop(BK) for 5€. Sponsors Praktijkvereniging BouT is looking for (main) sponsors. Sponsors make activities possible such as study trips, symposia, case studies, advertisements on Rumoer, lectures and much more. For more infos contact BouT: chairman@praktijkverenigingbout.nl If you are interested in Bout’s sponsor packages sent mail to: secretary@praktijkverenigingbout.nl � Copy Files for publication can be delivered to BouT in .docx or .indd, pictures are preferred in .png or .jpg format. Disclaimer The editors do not take any responsibility for the photos and texts that are displayed in the magazine. Images may not be used in other media without permission of the original owner. The editors reserve the right to shorten or refuse publication without prior notification.

Colofon

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CONTENT >Interview with James O’Callaghan<

>> National Staalprijz 2016 winner, The Paleisburg <<

_General 4

Debut vol.01

A small review of Value of Design

Events overview

_Engineering Articles 12

Structural Design of the Tokyo Skytree -Atsuo K onishi

Shock Safe Nepal-Jasper Sonneveld

Earthquakes explained -U-base

12 Questions for James O’Callaghan -James O’Callaghan

Extreme -Job Schroen

Structural Transparency, the Crystal House Facade -Faidra Oikonomopoulou

_Graduation Projects 54 60

Folded glass plate structures-Alkistis K rousti The Patching of Built Ornamental Heritage- Ali Sarmad K han

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EDITORIAL This issue is inspired from the Symposium Value of Design 2016, which had the theme of Extreme Forces.

We looked into Extreme Forces in the Building Technology industry. The following articles will inform you about the latest innovations of our field. The following articles are focused on materials and how extreme forces can influence the design. In our effort to make our magazine better each time, we decided to change the print in color and also enrich it with different types of articles. On that one you will find students articles, interviews, as well academic articles and graduation projects. We hope you will enjoy that issue as much I we did. And remember, you should expect more changes on the following issues! Popi Papangelopoulou RuMoer editor 2016-2017 7

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debut

v o l.01

On the 1st of June 2016 the first edition of Debut.event took place, an initiative by the Praktijkvereniging BouT. On this day about 60 students of Architecture and the Built Environment and Civil Engineering worked on cases provided by five leading companies. Booosting, the platform for innovators within the building industry was connected as a sponsor and the chairman, Robert Capel, acted as the moderator for the day. The five participating companies were: - Scheldebouw - IHC Studio Metalix - Bruil + Studio RAP - Hemubo - Saint Gobain, Interior Glass Solutions A very varied group with companies from every sector in the building industry. What they all have in common however, is the fact every one of them is concerned with innovative, creative and technical building solutions.

Scheldebouw presented a case where students had to develop a faรงade concept for a high-rise building in the heart of London, with special attention to the business model. Challenging, because of the many aspects of the city to account for, interesting because it offered many possibilities to integrate technology and architecture. IHC Studio Metalix brought a very concrete case with them: the optimization of a steel structure with steel cladding they are currently working on. As they are shipbuilders by nature they often approach a project like a ship and turn the hull upside down. As this project is still in progress the input from the students proved very useful and can be used to develop the structure further. Bruil collaborated with Studio RAP to bring their concept of 3D concrete printing to the next level. 3D concrete printing has reached a stage where it is important to look at the many possibilities this new technique has to offer to revolutionize the building industry. Students were asked to develop a concept for 3D printing in social housing, not a very innovative sector at first sight and thus all the more challenging to think of a feasible solution.

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Hemubo’s case also concerned social housing but with a somewhat different approach. Concepts had to be developed for sustainable social housing renovation options. The houses had to be retrofitted to net-zero-energy homes. It was also interesting to see how students approached this case, with their out-of-the-box thinking everyone got some new insight into the construction of energy-neutral homes. Lastly, Saint Gobain Interior Glass Solutions brought a challenging case to the table: the design of an acoustic glass partition wall. Glass’ natural properties do not make this an easy task and the students had to bring in all of their building physical knowledge to solve this case. With very good results because this group was elected by the jury (Robert Capel, Bas Gremmink and Christian Louter) to be the case winners of the day. After an intense but inspiring day it was time to head to the Faculty’s own Bouwpub for a few drinks to close the day. The first edition of Debut proved to be a great success, students and companies alike exchanged knowledge and got some very valuable insight into each other’s mind. Some of the cases developed even got a follow-up as a graduation project, what more can you wish for. See you next year!

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By Popi Papangelopoulou This spring we -the editing team of Rumoer- had the joy and luck to attend the fifth Symposium of Value of Design. This symposium is organized every 3 to 2 years from the student committee of U-Base and is sponsored by TUdelft, U-Base and an external sponsor. This year’s sponsor was Arcadis (Value of Design 2011-2014-2016) and earlier ING Real Estate (Value of Design 2005-2008). The purpose of the Value of Design series is to bridge the gap between engineers and designers, by showing to Engineering and Architecture students the great outcomes that can be achieved from the collaboration of those two disciplines. To prove their point even more, important experts from the building industry are invited to discuss on the idea of collaboration, through their experience and expertise via speeches and open discussion with the audience. The first Value of Design was held in April 19th of 2005 through the collaboration of U-Dispuut, The Dutch Council on Tall Buildings and the ING Real Estate and managed to gather 500 spectators. Its purpose was to introduce Architecture to Civil Engineer students and highlight the need of engineering knowledge into the architectural design to Architecture students. The first event was hosted by Mick Eekhout, professor at the Delft faculty of Architecture, while great Structural

Engineers and Architects were consisting the lineup of that event, such as: Raphael Vinoly, Philip Dilley, Leslie Robertson, Kevin Kennon, Ian Liddell, Ben van Berkel. The following Value of Design events kept the same philosophy and target group, thus on 2008 the symposium was entitled “Shared ambitions” and was held in the Old Church in Delft. On 2011 was entitled “Facing the Integration” and on 2014 was entitled “From bits to buildings”. The persistence of the organizers of that series of symposiums started enriching the culture of collaboration between disciplines, while TUDelft its self supported that idea, through its courses. As an example, we indicate our course guide, where courses of great popularity can be found, like MEGA, which is based on the multidisciplinary team work. MEGA is a course taught on the first year of the Building Technology Master and is accessible to Architecture, Building Technology, Real Estate and Civil Engineer students. After four Symposiums “Value of Design” enforcing the idea of collaboration between engineers and designers the firth one broad its theme to an engineering challenge, that of extreme forces. So, this year’s symposium “Value of DesignExtreme Forces” was held on 10 of May in the Aula conference building of TU Delft. Architects and

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Structural Engineers from international leading companies explained how the designer-engineer could use the extreme forces on his/her design and create a masterpiece and more important: How the cooperation of engineers and designers can enrich the building technology even more to the future, by realizing new visions. This year’s host was Siebe Bakker (Chairman of the day, Founder and Director of Bureaubakker, creator of 3TBouw) and the lineup was the following: James O’Callaghan (Director and Co-founder of Eckersley O’Callahan), Atsuo Konishi (Senior Structural Engineer of Nikken Sekkei), Ian Bogle (Director and Founder of Bogle Architects), Kamran Moazami (Director of WSP Group), Joep Tunnissen (Senior Advisor of Arcadis Nederland BV), Paul Kalhoven (Senior Partner, Head of Technical Desing of Foster and Partners) and. This year’s lineup presented projects under extreme natural phenomenon, like strong wind, earthquake and gravity, or brittle material, like glass that managed to be materialized through engineering and aesthetically qualities and brave visions providing cities with great modern landmarks. For more information the Value of Design organization committee inform us on their site (http://valueofdesign.nl/),Extreme Forces: Reestablishing the connection between architects and engineers

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For many decades, Architects and Engineers have been designing buildings for different environments and situations. At first sight it would seem like an engineering task to design buildings, in such a way that they resist these extreme forces. However, to reach the best possible results in terms of safety, aesthetics and economy, an integral collaboration between Architects, Structural Engineers and Building Engineers is necessary. By taking all the different aspects of a project into account from an early stage, and in an integral and multidisciplinary approach, long-lasting and visually appealing structures can be achieved. The symposium â&#x20AC;&#x2DC;Value of Designâ&#x20AC;&#x2122; highlights both the architectural part and the engineering part of several projects which have to deal with extreme forces, focusing in the collaboration between the two disciplines. We strive for a discussion about in which way we, architects and engineers, should conceive a project that has to deal with extreme forces. Such series of events carry great importance in many levels for the academic society. Firstly, is important that TUDelft, a famous Technical University that teaches engineering of different disciplines, to support such events, which promote the collaboration of different scientific fields. Secondly, for its students is nice and productive to meet all together in the same event and discuss concerns and fears for their future carriers with experts. And finally, for Building Technologist in particular that were created as field to fill in the gap between Engineers and Architects, symposiums like Value of Design teach us what we can achieve and in which way we can find our place in the building industry.

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Structural Design of the

TOKYO SKYTREE by Atsuo K onishi,

Senior Structural Engineer, Structural Engineering Department, Nikken Sekkei Ltd., Tokyo, Japan . email: konishi@nikken.jp

Introduction

TOKYO SKYTREE(Fig.1) is a new core facility for digital broadcasting for the Tokyo metropolitan area of Japan. It is 634m (2,080ft) high and is the highest tower in the world for broadcasting, and was completed in 2012. It is expected to be a tourist attraction, a base for broadcasting and telecommunications, and a quasi-disaster prevention centre of the Tokyo metropolitan area. The requirements for structural designs in Japan are extremely severe, because several typhoons strike every summer and big earthquakes occur with high probability. Consequently, TOKYO SKYTREE was required to adopt high criteria, exceeding the building regulations in Japan, because of its heavy public responsibility to send valuable information to victims in a big disaster. Furthermore, the structural characteristics of this tower are different from those of other domestic structures, so a new design method had to be invented especially for earthquake and wind resistant design. The Core Column System, unique system for vibration control, was invented for this tower to satisfy the requirements for structural design. Generally, steel towers have poor damping capacity, and improvement in damping ability was demanded for this tower. The Core Column System uses a core shaft of an emergency astaircase comprising a reinforced concrete tube wall as a weight, using the theory of TMD (tuned mass damper).

Figure 1. Tokyo Skytree

Structural Planning

This tower varies in silhouette, according to alteration of plan shapes: the bottom floor is triangular and the observatory floor is circular (Fig. 2). Steel structures comprising pipe trusses were adopted to decrease weight and area presented to the wind that contributes to decrease power generated by the wind and pressure of residents around who always sense vaguely to the massive structure. Circular sections have fabrication and welding advantages compared with box sections, and make possible a roundish silhouette. The maximum pipe strength is 630N/mm2, the maximum diameter is 2,300mm, and the maximum thickness is 100mm (Table 1). The frequency of each member was designed to be large enough to prevent vortex induced vibration up to strong wind â&#x20AC;&#x153;L3â&#x20AC;?: 2000-year return period in Table 2.

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Table 1. Design Criteria

Table 2. Assumed Disturbance

Figure 2. Superstructure

Figure 3. Notion of boundary layer

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Figure 4. Balloon launching system

Figure 5. Observation of wind with GPS Sonde

Figure 6. Entire wind tunnel test

Figure 7. Wind tunnel test for portion

The in-service period for disturbance of the structural design of this tower is 100 years, which is longer than that for an average building in Japan, because this tower is expected to be a quasi-disaster prevention centre of the Tokyo metropolitan area. In addition, this tower has “L3” level criteria defined by the return period of a disturbance that the building regulations in Japan1)2) don’t require, and that ensure that the tower will resist an unexpected big disaster (Table 2). The “L3” level assumes an earthquake resulting from the activity of hidden faults. Many faults have already been investigated in Japan, but a small earthquake

under M7.3 doesn’t leave a track on the ground surface. This criterion assumes the existence of such a hidden fault immediately under this site. This assumption is offered by the Japanese government, and geological survey has verified that no fault exists immediately under this site. The structural safety limit according to the “L2” disturbance (in Table 2) for this tower is almost no damage, and it is the criteria to continue broadcasting and to support revival of victims in a big disaster, and the “L2” disturbance is the maximum level that the building regulations in Japan require for domestic buildings. The regulations for the vibration velocity in frequent

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wind were established for the Gain Tower; the top of the tower and the broadcasting antennae.

Characteristics of aerological wind

The structural design of this tower was based on wind induced response rather than seismic response. It is most important for wind resistant design to define the wind profile of average wind velocity from the ground to the top of this tower. However, the development of boundary layer wind depends on the surface roughness of windward side ground, as shown in Fig. 3. Thus, observation of aerological wind3) over this site was an essential condition to determine the wind characteristics and to carry out wind resistant design. A wind profile was inferred from previous studies to define with power law, but no one knew the height of wind in gradientwind-balance over this site. First, the observation of aerological wind was planned by a wind profiler and GPS Sonde (Figs. 4, 5). A wind profiler is an instrument for observing aerological wind velocity using a sound wave, but the sound is too loud to use downtown. Thus, there was no alternative to using only the GPS Sonde. With this method, balloons are released in wind and transmit their position every second by GPS to a base, enabling wind velocity to be easily determined. 50 balloons were launched from the roof of a building near the site, and it was observed that the average wind velocity was constant from 1,000m to 1,300m. It is difficult to define the height of wind in gradient-wind-balance because there were too few observations for accurate estimation. However, from this research it was decided to accept a power law under a height of 634m, the top of the tower, to define the wind profile for wind resistant design.This site is located in downtown Tokyo, but the surface roughness for wind resistant design is the same as that for the bay area. Enough distance from the coast is needed to develop a boundary layer up to the top of this tower, and this site is only 8km from the coast. The turbulence effects within the atmospheric boundary layer were extrapolated from previous studies.

Figure 8. The history response analysis with wind fluctuation data

Verification of structural safety for wind response

Boundary layer wind tunnel simulations were executed that simulate behaviors of this tower against airflow generated as natural wind observed over this site, and the wind response was thus directly verified (Figs. 6, 7). The stability and wind response were analyzed by time history response analysis with artificial wind fluctuation data that simulated the wind tunnel test results. Artificial wind fluctuation data were created, targeting the power spectral density of fluctuation components obtained by the overturning moment of the base level in wind tunnel experiments, and this was one of the Monte Carlo simulations (Fig. 8). It is possible with this analysis to verify the safety of members, the effect of the vibration control system, the fatigue failure of welding, etc. The procedure of the wind resistant design developed for this tower is shown in Fig. 9.

Outline of vibration control system 15

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Figure 9. Flow of wind resistant design

The structural design of this tower, for example the decision on member sections, is decided from wind induced response rather than seismic response. But it was clarified in basic study that acceleration during an earthquake is too large to operate the instrument for broadcasting unless damping is added as a vibration control system. As unique systems for vibration control, the Core Column System s (Figs.10,11,12) was invented for this tower to satisfy the severe requirements. Generally, steel towers have poor damping capacity, and improvement in damping ability was demanded for this tower. The Core Column System uses the core shaft of the emergency staircase built with a reinforced concrete tubular wall as a weight applying the theory of TMD (tuned mass damper). The Core Column System works the role of an added mass. This column comprised a circular cylinder of

reinforced concrete, and had a diameter of 8.0m, a thickness of 600cm, and a height of 375m. It was free from the main steel frame of the tower. The upper half was connected with oil dampers and the lower half was connected with steel members. Therefore, it is a column but it is independent of the tower and doesnâ&#x20AC;&#x2122;t support the towerâ&#x20AC;&#x2122;s weight. This vibration control system is effective over a wide range of earthquakes. It can reduce the acceleration response during an earthquake by a maximum of 50%, and a that during strong wind by a maximum of 30%.

Conclusions

TOKYO SKYTREE is a new core facility for digital broadcasting for the Tokyo metropolitan area of Japan, and it requires strict design criteria because of its heavy public responsibility to send valuable

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information to victims of a big disaster. The maximum disturbance for the structural design of this tower is the strong wind of 83m/s for 10 minutes mean value at its top, and the structural safety limit for the disturbance is elastic behavior. The Core Column System, unique system for vibration control, was invented for this tower to satisfy these requirements. The Core Column System uses the core shaft of the emergency staircase comprising a reinforced concrete tubular wall as a weight applying the theory of TMD (tuned mass damper). This vibration control system is effective over a wide range of earthquakes. It can reduce the acceleration response during an earthquake by a maximum of 50% and that during strong wind by a maximum of 30%.

Oil damper The Core Column Movable range plan

The Core Column

Movable range

REFERENCES 1) Ministry of Land, Infrastructure, Transport and Tourism (MLIT), Japan: The Building Standard Law of Japan, June, 2007 2) Architectural Institute of Japan (AIJ), Recommendations for Loads on Buildings, 2004 (in Japanese) 3)Ministry of Construction, The Building Center of Japan, Hyper-Building Laboratory, â&#x20AC;&#x153;The wind force for hyper-building designâ&#x20AC;?, January, 2002 (in Japanese)

Figure 11. Section of the Core Column

Immovable range

Figure 10. Notion of response control system with the Core Column

Figure 12. The Core Column

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Shock Safe Nepal

A student initiative to help rebuild Nepal against devastating earthquakes.

On the 25th of April 2015, a devastating earthquake struck Nepal. Over 8.500 people died during the earthquake and 200.000 houses were destroyed by this terrifying force of nature. Ever since, Nepalese people are fighting to rebuild their homes and make their country liveable again. Already before the earthquake, Nepal was a country struggling with large groups of the population living in absolute poverty. Now that their houses have been destroyed, water sources have run dry and parts of the main infrastructure has been annulled, this struggle to escape poverty has had a major setback. Therefore, the Nepali face an immense task at hand in rebuilding their country. To support them in this mission, the Shock Safe Nepal initiative was founded by students of the TU Delft with the main objective to rebuild the lost homes, while minimizing the risk of collapse during future earthquakes. In this project the knowledge of TU Delft students on building techniques, structural loads, architecture and organisations is addressed in order to support the Nepali in reconstructing their houses. Up to now (juli 2016), two multidisciplinary teams of students have travelled to Nepal to perform research on how this main objective can best be achieved. The third team is currently in Nepal and will test the applicability of the findings. Figure 1: Nepalese house destroyed after the 2015 earthquake

Strudentâ&#x20AC;&#x2122;s article

Extreme Forces With all combined efforts of all Shock Safe Nepal teams, the vision is to rebuild Nepal shock safe. But what exactly does this comprehend? As most students of the TU Delft have no extensive knowledge on building houses in Nepal, the first two teams have conducted research on the country itself, the old building methods of the Nepali and have created a damage inventory. By now the third team is in the phase of converting all these ideas into feasible designs for small houses on the country side as the most catastrophically hit areas find themselves in the rural regions of Nepal. The people in these areas are basically cut off from the outside world, have to travel huge distances to the nearest markets and have trouble cultivating enough food for themselves to last the year. The climate in Nepal does not help these people as it barely rains besides the monsoon season which only lasts from July until September. Before the earthquake, this problem of a lack of water could barely be solved by water sources in the mountains but the earthquake has dried up over half of the water sources in the affected regions. In combination with the Nepali still living in temporary shelters, these people are in dire need of help. But helping is not easy in this traumatized country. Logically, the government wants to control the reconstruction as they want to be involved in the rebuilding of their own country. They felt that they already were too dependent on the help of other countries and NGOâ&#x20AC;&#x2122;s during the first emergency

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relief after the earthquake. However, even in the phase following the emergency relief, the phase in which the reconstruction has to commence, the government has trouble managing the enormous organization that is required to rebuild the country. Due to the number of houses that has to be rebuild, the government has had to create a system in which all money is distributed evenly among the former house owners. This on itself would already be difficult in a western country, but in a country like Nepal where most of the people in rural areas donâ&#x20AC;&#x2122;t have bank accounts it becomes even more challenging. Let alone the culture shock which has to take place in order to start building shock safe. All over Nepal, and mostly in the rural areas, people have never learnt to build using methods that make houses less prone to earthquakes. To bring this knowledge to the people, a huge amount of engineers is required to oversee the reconstruction. By now the government has already trained 1400 new engineers which will all be assigned to the so called Village Development Committees to share their knowledge with whoever is going to rebuild their house. On top of this, the government has created a design catalogue which is supposed to show the people how to build earthquake proof with several materials, ranging from stone masonry in mud mortar to brick masonry in cement mortar. But our experience is that this catalogue lacks consistency and understandability. The Nepali people are unable to understand exactly what they are expected to build and will therefore

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fall back into their old construction techniques. That is the problem that Shock Safe Nepal envisions to solve, translating (and improving) the Nepali building code into understandable and feasible designs for the people of Nepal. One of the problems in building in rural areas is the availability of materials. To create feasible houses, most of the materials will need to be locally available. Otherwise the costs of transport to inaccessible areas will double the cost of housing, money that the Nepali donâ&#x20AC;&#x2122;t have. Therefore, Shock Safe Nepal is developing three designs of different local materials which can help the people of rural Nepal to reconstruct their houses. Materials that are available in large quantities in rural areas are stones, clay and to a lesser extent, wood. Although a small quantity of materials will have to be imported, the designs focus on using mostly these materials. Using these materials the most feasible building methods have shown to be the use of rammed earth, stone masonry in mud mortar and compressed earth bricks.

however if most of the stones are forced to move in the same direction the house will move as one rigid construction and if properly connected to the foundation, the house will withstand the earthquake. The stones are usually the weakest link in the walls and if a wall is completely made of stones it will not be able to absorb the forces of the earthquake and will most likely collapse. By adding horizontal and vertical beams inside or against the walls these forces are absorbed by the beams and if connected properly throughout the house, the house will start to function as a rigid construction instead of a variety of stacked stone walls. These beams are usually made of reinforced concrete, but to create feasible houses in rural Nepal (where cement is not locally available) wood is a far better option. As long as the structure of the house is rigid and the walls of stones, rammed earth or compressed earth bricks are regularly interrupted by reinforcing to absorb the energy, the houses stand a much bigger chance against future earthquakes. Jasper Sonneveld

The use of stone masonry has already been well known in most parts of the country, however, without reinforcements these buildings donâ&#x20AC;&#x2122;t stand a chance against an earthquake as strong as the one from April last year. The problem with the old houses can be found in the connection between all parts of the house, they were all separate parts and unable to move as one. It is unavoidable that the house is going to shake during an earthquake,

Shock Safe Nepal Group

Studentâ&#x20AC;&#x2122;s article

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5 STEPS for designing

SHOCK SAFE BUILDINGS

1 FOUNDATIONS

Foundations are the key to build shock safe. They should be strong and be well connected to the building to allow vibration but to avoid collapsing.

2 MATERIAL CHOICE

3 CONNECTING

Connections should be made to make the building move in only one direction as one rigid construction.

5PROPORTIONS

Each material should be carefully chosen to be flexible and in harmony within the building, a wooden construction doesnâ&#x20AC;&#x2122;t work well in combination with concrete.

4 REINFORCEMENT

Small elements (like brick walls) should be reinforced with larger elements to prevent all the small elements to move in different directions.

Proportions are really important as well. Out of proportions part of the building will collapse first. A ratio of 1:4 is not to be exceeded.

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EARTHQUAKES EXPLAINED Gas

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Strudentâ&#x20AC;&#x2122;s article

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original Dutch article by Carla Smulders, U-Profiel/ U-BASE We have all heard of it lately: the earthquakes in the province of Groningen that are being caused as a result of our own gas extraction. We also know that research is performed here at TU Delft concerning these earthquakes. But what is really going with them? What do they research in Delft and also in the Italian city of Pavia? And are there any results yet? First of all, let’s find some background information regarding these earthquakes, since they are quite extraordinary. Before 1986, earthquakes were never recorded in the north of the Netherlands, but since then there are recorded over one thousand of them. We know that they are being caused due to our own gas extraction, but what is the exact relationship between them?

on places where the ground subsides compared to those places where nothing happens, the ground will move. This ends up in earthquakes. Currently, there are about 50 earthquakes each year. These are all caused by the gas extraction in Groningen. Figure 2 shows all earthquakes from 1986 until 2016. In 2012, an earthquake of 3.6 on the Richter scale was recorded near the town of Loppersum, which was the heaviest until then. However, this does not seem to be a really heavy earthquake. So what are we so worried about, then?

Gas extraction A lot of gas is extracted in Groningen. This gas is mainly present in rock, sandstone to be more specific. Sandstone is sand that sticks together because it is held under pressure. Between the sand particles, pores are left over. Underneath the layer of sandstone, all organic material decays which results in gas that slips inside the pores. If we extract the gas, the pressure in the pores is being lowered and because of the heavy weight of the rock above, the pores can collapse. This causes what is called tectonic subsidence. If gas is being extracted Figure 1(on the previous page): The typical ‘X’ fracture as shown on a wall at the TU Delft test house. (Source: NRC)

Figure 2: All earthquakes (orange) in Groningen from 1986 until September 2016. The gas fields are shown in green. (Source: Kor Dwarshuis)

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The effect of an earthquake is not only determined by its strength, the Richter scale. There are a couple of other factors that influence the effect of an earthquake. One of these factors is the depth of the source. In Groningen this depth is very little, which barely weakens the magnitude and thus the earthquake is felt relatively heavy at the surface. Another factor is the soil composition in Groningen. Since this composition is very weak, the soil shakes even more and makes the earthquake even a little bit more powerful. The reason why the earthquakes are increasing in power could possibly be the continuous drainage of the rock which contains the gas. This causes a negative pressure inside the pores in such a way that the rock collapses with more and more force. If the earthquakes in Groningen become even bigger, soil liquefaction can occur. This means that loose sand particles will compress, only that the water in between does not have enough time to flow away. As a result, pore water pressures occur, which can lead to contact loss of the soil skeleton and thereby the loss of the complete strength of the soil. In the end, the ground level locally and suddenly subsides. If we would quit right now with the gas extraction all problems will not directly be solved, since Groningen is stuck with a very large delay. The gas extraction has started in 1964, but the first earthquake was not until 1986: that is a 22 year delay! Even the increase of the power of the earthquakes does not stop if the gas extraction is terminated.

Research TU Delft In the past years there are many different projects set up due to the earthquakes in Groningen. One of these projects contains a research into the dynamic response of brick houses and into the materials inside a these houses. The brick houses are never designed with the purpose of being resistant against heavy earthquakes. This is exactly what is examined in Delft, among other things. How strong are these dwellings? How many load can they bear? Where exactly are the cracks occurring and how do they increase? Answers to these questions are found with the help of test walls and even with complete test houses up to two stories high.

Dynamic response The research into the dynamic response of a brick house goes as follows: a two-storey dwelling is cyclically loaded during a so-called cyclic quasistatic pushover test. This means that the soil of the building is fixed and the upper side of the building is being pushed and pulled in horizontal direction with a maximum amplitude of 8.5 cm. On various moments the load is taken away temporarily, after which a hammer is used to give an impulse (both horizontal and vertical) where sensors measure the vibrations inside the dwelling. In this way, resonant frequencies for different damage levels are being determined. It turned out that the resonant frequency strongly decreases

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if the dwelling is already heavily damaged at the moment of the impulse. During the cyclical tests, the loads, deflections and fracture patterns were monitored accurately. A fracture pattern in the form of a large ‘X’ on a wall showed out to appear often (see figure 1). All of the stored data will be analysed and used to validate and improve existing EEM models. This data will also be used to get a better understanding of the response of the brick houses during an earthquake.

Sand-lime brick Research into used materials inside a brick house showed that, among other things, sand-lime brick is more ductile than assumed. The tests concluded that a sand-lime brick wall, subjected under an increasing perpendicular load, can deflect up to 8 cm out of the plane. This type of brick is used a lot in Groningen terraced houses with a cavity wall construction for the inner bearing walls. These houses (which can be found a lot in Groningen) are extremely vulnerable because if one bearing wall collapses, there is a chance that one house collapses together with the whole terrace. There was little known about sand-lime brick until now. Its ductility says something about how a wall can deflect and crack permanently before it collapses. This conclusion is therefore useful for the load capacities of Groningen dwellings.

Research crew of the TU Delft in their earthquake test house. (Photo: Frank Auperlé)

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Pavia research The Dutch oil company NAM (Nederlandse Aardolie Maatschappij) also allowed research at Eucentre, a centre for earthquake research in Pavia, Italy. At this centre, cavity walls, half-brick walls and smaller masonry work are being tested. Moreover, a complete dwelling built by Groningen bricklayers with bricks and mortar which are used in Groningen, is located at Eucentre. In the first instance, a typical 1970s house with a through-lounge was chosen. On the ground level of this house type there are little to no partition walls, causing this type to be extremely vulnerable. The house chosen is very common in the Groningen earthquake area. The test house was placed on an earthquake shaking table to test it for all kinds of loads. The dwelling was tested for heavy earthquakes with a peak ground acceleration (PGA) of 0.326 g. This PGA is significantly more than the 0.086g that was recorded during the 2012 Groningen earthquake. Besides that, the test earthquakes lasted for 2 to 2.5 seconds, slightly longer than the 0.5 to 1 second lasting earthquakes in Groningen. Still, the house did not collapse, which led to quite a surprise for the Italian researchers. A possible cause for this larger load capacity than was expected at first sight, could have to do something with the flange effect. The cornerstones of the perpendicular walls are built in such a way that they interlock, which could give the construction extra stiffness.

With the results of the latest research, the standard deviation of the vulnerability curve decreased. This is a curve where the load is plotted against the damage to a building. Ever since, it can be predicted what the resilience of a dwelling is. However, variation is still possible. Since the 1980s there have been used more and more limestone elements, which do not interlock at the corners. There is also a large variation in the quality of the masonry per dwelling. For example, there can be found both good and bad quality brickwork in one and the same house. Furthermore, many older dwellings have had restorations and other changes in the course of years. The sizes of the stones and the thickness of the walls differ per dwelling and even per wall. Every house should therefore be examined individually. The NAM now has a better picture of which dwellings are more vulnerable and have to be reinforced. In addition to that, the EEM models can predict more accurate what the effects of an earthquake on brick houses will be in the future. Moreover, new courses and disciplines about earthquakes are being set up at this moment including a new national enclosure for Eurocode 8. Currently, companies use the guideline NPR 998 for calculating buildings in the earthquake area.

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Sources Aan de Brugh, M. (2015). Groningse huizen zijn best stevig. Retrieved

from

www.nrc.nl/handelsblad/2015/11/21/flink-

schudden-aan-groningse-huizen-ze-zijn-best-1557758

Dwarshuis, K. (2016). Gas drilling in Groningen gas field, the Netherlands causing shallow & destructive earthquakes â&#x20AC;&#x201C;

realtime.

Retrieved

from

http://www.dwarshuis.com/

earthquakes-groningen-gas-field/visualisation/

PĂŠrez, N. (2013). Steeds meer aardbevingen in Groningen: hoe gaat dit in de toekomst verder? Retrieved from www.scientias. nl/aardbevingen-door-gaswinning-wat-is-het-probleemnu-eigenlijk

Wassink, J. (2016). Pushed to pieces. Retrieved from http:// delta.tudelft.nl/article/pushed-to-pieces/30960

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Programmable Structures and Materials How 3D printing and new software can revolutionize the AEC industry By: Maarten Mathot, Engineer at White Lioness technologies. Jeroen Coenders, Founder White Lioness technologies & BEMNext lab research leader at Delft University of Technology.

Now that the 3D printer has found its way to the construction site, the building industry is on the edge of a revolution. Few years ago, 3D printing of building structures was still hard to imagine, but nowadays more and more succeeded experiments are being reported. Amongst the first success stories are a 3D printed concrete apartment building in China and office in Dubai. Many believe 3D printing can bring great disruption to the construction industry in the near future, and some at NASA even expect 3D printing of concrete to be the fastest growing market worldwide in the years to come. With the potential of 3D printing in mind the BEMNext lab at Delft University of Technology is ready to take the next step: towards material properties that can be programmed by laying out the material in an advanced 3D printed pattern. Benefit can be that materials and structures can behave according to the desire of the designer in terms of structural behaviour or building physics. Inspiration came from a lot of research on various optimisation techniques which has been performed within the lab in recent years, but the full implementation of these techniques on buildings has often been hindered by constructability constraints. With the advent of 3D printing, many of these constraints are removed and a different

way of designing and constructing buildings can be envisioned. Under the name of Programmable Structures and Materials the lab is performing research in this field. In this article BEMNextâ&#x20AC;&#x2122;s vision on what Programmable Structures and Materials may bring to the industry is explored, along with the first steps the lab is taking in this direction.

Programmable Materials

One of the great benefits of 3D printing, besides for instance the reduced labour cost, is the great level of detail with which the placement of material can be controlled. By deliberately choosing what parts of an object contain material and what parts are left void the properties of the object can be greatly influenced. One can imagine that placing material in a truss-like configuration can greatly enhance the structural performance to weight ratio of an object, and a conscious placement of voids can increase the insulation value. Additionally, as the object can be printed for placement in one unique position in one building, the specific boundaries and requirements at that position can be taken into account during optimisation. 3D printing does not only provide greater control over where material is and is not placed, it can also be used to apply different materials throughout an object. Much like reinforced concrete, a combination of materials can employ the beneficial properties of each material in the place where those properties

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Credit: L. Meza, L. Montemayor, N. Clarke, J. Greer/Caltech https://www.caltech.edu/news/miniature-truss-work-42850

are required most. While the benefits of these composite materials to structural performance are easiest to envision, the physical performance of a building can be enhanced as well: by for instance placing insulation or transparent materials in a wall the climate of a building can be influenced.

Materials vision: By controlling what material is placed where on a small scale, materials and objects can be created that behave exactly in the way the designer desires. The greater the precision with which the material can be positioned, the greater the range of material behaviour that can be designed.

Recent research at CalTech1 shows that the level of detail with which one can place material can be immense: ceramic truss structures can be created on micro- to nanometer scale. Any object made with such so-called structural metamaterials has vastly different performance than an object made out of the base ceramic material: in terms of structural performance they can be very stiff whilst being very lightweight, ductile rather than brittle material behaviour is observed and even recovery after deformation is possible.

Currently, the BEMNext lab focuses on placing materials at a larger scale, for instance in a project where concrete is printed with a resolution of approximately 4 cm. At this level of control, the freedom of designing behaviour is obviously limited, but at least physical experiments can be performed at reasonable cost. Furthermore, it enables testing of ideas in a setting that is tangible and relatively close to construction site adaptation.

Obviously the application of engineered materials on nanometer scale in building construction is currently, and may always remain, economically and technically infeasible. It does, however, illustrate the main idea behind BEMNextâ&#x20AC;&#x2122;s Programmable 1 Greer J.R., Materials by design: Using architecture and nanomaterial size effects to attain unexplored properties, Bridge 45(4), 37-44 (2015)

Programmable Structures

The possible effects of adaptation of 3D printing techniques on the design process are considerable. Because structures can now be influenced in great detail, the design should be very detailed as well. The exact positioning and specification of the material at every location can no longer be

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done by designers and engineers in conventional ways due to time- and budget constraints. To be able to employ the potential benefits in terms of material performance and efficiency provided by Programmable Materials, a paradigm shift needs to be made in the way we currently design buildings. Much like in conventional design a line needs to be drawn to what level of detail a designer actually designs his or her building, and what is considered beyond his or her control. Conventionally this line more or less lies at specifying a material in which an object needs to be created. Even though the 3D printing techniques offer a vastly wider set of possibilities at greater levels of detail, the designer will probably not be designing at a greater level of detail. He or she does not necessarily has the knowledge required to design at this level, and spending time to design every minute detail might result in fewer design iterations. The task of designing on this smaller scale can better be performed by software. Given the right control, optimisation algorithms can explore a great range of possible materialisations in a small amount of time. They also assess the performance of the materialisations resulting in one or multiple best performing options. These typically require an unambiguous description of both the restrictions with which any acceptable outcome needs to comply and the goal, for instance a combination of factors describing structural and physical performance. Due to the fact that 3D printing allows for a greater range of constructible geometries in comparison with conventional construction techniques, it may be beneficial to actually stop designing at an even coarser level of detail than currently is commonplace. Certain optimisation techniques can explore a vast variety of alternative designs, even at the scale of entire objects. By combining these larger scale search optimisation with optimisation of

Programmable Materials, buildings can be realised with a never before seen level of performance. Given this prospect, it is clear that the role of the designer and engineer within the design process will change. Rather than designing a geometry his or her task will shift to defining both optimisation restrictions and the desired behaviour of the building. Consequently, optimisation algorithms can come up with high-performing alternative designs. As certain desirable properties, for instance aesthetics, are hard if not impossible to quantify, the designer would then pick one of the provided alternatives.

Current research at the BEMNext lab

As mentioned the BEMNext lab has started the research in this area. Among the first projects currently being performed is the 4TU.Bouw Lighthouse project on Optimising 3D Printed Concrete in collaboration with Technical University Eindhoven and White Lioness technologies. In this project optimisation software is being developed which takes into account the possibilities and limitations of a building scale 3D concrete printer, as available at TU/e, and the printed concrete itself. Subsequently, the gathered information is used to develop the software in which optimised yet printable structures can be designed.

Join the team

The BEMNext lab has a vast amount of research ideas to be picked up: for example transforming vision into reality, developing powerful optimisation software which can run on the cloud simultaneously to explore possible design alternatives, pushing the boundaries of 3D print technology for building construction. If you are interested in doing research in this field, check out the website www.bemnext.org or contact Jeroen Coenders at: j.l.coenders@tudelft.nl

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Dr. Jeroen Coenders

Maarten Mathot

CEO, Founder, White Lioness technologies

Project Engineer, White Lioness technologies

Assistant Professor, BEMNext lab, Delft University of Technology

Graduate, BEMNext lab Delft University of Technology

“Technology can help mankind to create a more sustainable and prosperous future”

“The construction industry could benefit more from the rapid developments happening in other industries”

Jeroen Coenders (1978) is an entrepreneur, researcher and developer since his early childhood with a great fascination for what technology for the built environment can mean.

As Project Engineer at White Lioness technologies, Maarten Mathot (1989) is currently involved with the management of the Lighthouse project on Optimising 3D Printed Concrete. Within the BEMNext lab he actively contributes to the establishment of the Programmable Structures and Materials research branch.

Jeroen graduated with honors and obtained his PhD from TU Delft on next generation design systems for the AEC industry. Currently, he is responsible for a virtual lab at the Faculty of Civil Engineering and Geosciences, named BEMNext, where research is being performed by students in collaboration with companies about the next generation modelling technology for the built environment. Jeroen has worked nearly 10 years for Arup in Amsterdam where he was responsible for complex structural projects such as Arnhem station and the software of the tallest free-standing TV tower in the world, the Guangzhou TV & Sightseeing tower. In 2013 Jeroen and co-founder Anke Rolvink started White Lioness technologies. White Lioness technologies develops Packhunt.io, a new platform which helps clients with challenging problems relating to transforming (big) data into meaningful information and digital knowledge.

During his studies at the Faculty of Civil Engineering at the TU Delft he developed a passion for structural engineering, but always wondered whether the construction industry could not benefit more from the rapid developments happening in other industries. For his MSc thesis at the BEMNext lab he is developing new ways to capture, store and automatically retrieve engineering knowledge in the AEC industries.

Contact information White Lioness technologies BV Attn Jeroen Coenders Van Diemenstraat 118 1013 CN Amsterdam 020-737 1997 www.bemnext.org www.white-lioness.com Twitter @jeroencoenders LinkedIn: www.linkedin.com/in/jeroencoenders

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12 QUESTIONS FOR JAMES Oâ&#x20AC;&#x2122;CALLAGHAN By Alkistis Krousti and Eleftherios Siamopoulos

On the 22nd of March we had the opportunity of having a very insightful interview with James Oâ&#x20AC;&#x2122;Callaghan, currently Visiting Professor at Delft University of Technology. Read further to dive into innovative glass structures, sustainability, collaboration and the future of young engineers.

1. A lot of people consider glass structures, and especially the Apple stores, as your trademark. How did you first get involved with structural glass? I first got involved with structural glass in 1995, which seems like a long time ago now. I was involved because I worked for a structural engineering company in London, called Dewhurst Macfarlane & Partners, very much at the forefront of exploring what you can do with glass structures. A little bit like Rob Nijsse here, Tim Macfarlane was my mentor at the time and I was playing around with his ideas about using glass as a structural element. I suppose because I was working with him, completely coincidentally, I began to understand the idea and saw the potential in it. What I was most intrigued

about was the development of the connections. I saw that these were a more important aspect of structural glass design than the elements themselves. That drew me into it more and more and then we were lucky enough, within my time, to do some pretty iconic and valid progressive structures. Which then led to Apple, when I was doing my own practice, and years later that sort of theme in my involvement in engineering continued through them. The reason that glass is with Apple is not because they came to us about glass. In fact, it is because we brought glass to them.

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Extreme Forces 2. So how did the approach happen? Was it the architect that came to you with a glass idea or was it the other way round? Yes. Well, the architect certainly came to us with an idea about the retail space that we were looking at, and how to make the most of that space. The concept of the glass came out of that. It started off as a steel stair, with glass elements in it, and it evolved into a fully glass structure, really through Apple’s determination that they wanted it to be more ambitious than perhaps the ideas presenting a steel and glass stair. So, they drove it to that point, but they only did so on the basis that they knew they could get there, because they had the right people, the architect with the right idea, and the engineer with the right knowledge to be able to make that happen. So it was a very collaborative process, really, to get to that point. You can’t do things like that without a brave client, without a great supply chain and people to work with, architects, designers, etc. Thankfully, all those people came together and that’s how it started!

3. Would you say this is your most ambitious design to date, the design that you started with, or have there been more ambitious ever since? That’s a very good question. You know, you can always look at things in perspective but of course, when we first did it, it was an incredibly ambitious thing. It’s a very good question about whether anything we do today, will ever feel like as it did back then. The sure answer of course is no, everything we do now has that history baked into it and that experience baked into it, so we are able to push the boundaries a little bit more each time. So of course

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“I think the sustainability theme has been around for a long while, but it certainly gathered momentum in the last few years, so that it now impacts pretty much everything we are doing.”

what we do now is far more technically ambitious than we did then, but does it feel like it is? Well, maybe not.

4. So what is the most ambitious design you are working on these days? Well, we are working on a number of projects that we cannot really talk about, most of the things that we do these days we must not talk about to respect the wishes of our clients! We are working on some rather big ideas, taking the same ideas, and making them bigger, on bigger buildings, with more transparency, higher complexity; in the way in which we connect things and we deal with energy, solar gain and things like that. We are doing a very nice project in London, one thing that I can talk about, for two glass bridges between two existing buildings. It is a box bridge, a roof of carbon fibre, walls of

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glass, and a deck of stainless steel. None of this is cladding, all the elements working as the envelope and as the structure, so the result was a very fine, very thin profile. So that one is in the public domain, other things are a bit more protected I am afraid.

ways of controlling heat. We are no longer trying to find more complex mechanical shading devices, the world has enough of those already. It is more about how we can make glass take that role and how you combine that with more intelligent architecture.

5. Since you mentioned sustainability, are you concerned with sustainability in your work and how does this reflect in the glass structures?

6. What is set as the final goal in structures like this? Is it only directed towards maximum transparency or are there other objectives?

Yes! I think the sustainability theme has been around for a long while, but it certainly gathered momentum in the last few years, so that it now impacts pretty much everything we are doing. So what we found is that we have been focusing on glass and the structural performance of glass, the size, the transparency and we have met a point at which the control of energy is currently prohibiting further development without more of a development on how we control the energy within buildings. So now, we definitely have a focus on how to make our buildings more sustainable in terms of their energy. I think it is firstly about the whole building’s design, how a building can be ‘intelligent’ in terms of the use of light and recognize that south facing glass buildings in the northern hemisphere are not going to be easy. Of course the technology on the glass itself needs to be improved, to find more effective coatings and

I think maximum transparency is nice, but it is only maximum transparency when you want it; I mean nobody wants to live in a glass house! So it is the application, it is making this dynamic environment comfortable so that you have as much light as you want when you need it. That has got to be the goal for most glass applications. Of course, that is when we are talking about a building envelope, but we are also using glass in so many ways, such as a bridge or a staircase, which have more of a feature about them. So in terms of that point, the end goal is, without reinventing the material in itself (which would be great because it has so many flaws) how we can improve the connectivity and the opacity in order to get to a truly all glass structure. An all glass structure which can accommodate all form of geometry, in any complexity, under any load is where we are getting to.

“The staircase for example, is not a structural element; it is an element hanging within a structure” 34

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7. How does a brittle material like glass behave in earthquake sensitive areas? For example, in the case of the glass staircase in Los Angeles, the hanging construction allows for lateral sway. How much can the staircase deflect in lateral direction? How are the connections resisting these deflections? The best performing seismic structures have the ability to absorb energy. So steel and concrete are detailed in certain ways to dissipate energy from natural accelerations in order for the structure itself to not be overdesigned to accommodate these significant forces. In glass you cannot easily do that because glass has zero plasticity. It is a 100% elastic material which means that it will â&#x20AC;&#x2DC;feelâ&#x20AC;&#x2122; the full force of that earthquake and it can only be designed as such. The way you accommodate it is, in the case of a free standing structure, that you have to detail it such that the rigid elements can move and in turn dissipate energy, relatively to one another. That tends to be within the detailing of the connections, rather than in the glass itself. The staircase for example, is not a structural element; it is an element hanging within a structure, so its detailing has been made so that these movements can be accommodated. Firstly, knowing what the movements will be, what that means to the detailing, but also what that means to the forces that will get imposed on the glass. So it is kind of an iterative loop of understanding movement, detailing, and forces being put to structures as a result of this movement.

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8. Where do you see glass architecture going in the future? Which seems like the most promising innovation? We have talked a lot really in terms of what we see the future as. Glass is generally used as a building envelope material. That is where innovation needs to be, in more dynamic glazing. That is the only way we can start responding to the changing agenda of sustainability and the rapidly changing energy codes. Otherwise, in 10 yearsâ&#x20AC;&#x2122; time every building will have 40-50% less glazing, which is going to be not only more miserable for us, but also more miserable for the glass people, who will need to produce 40% less glass. So it is quite an agenda for them to be able to solve the problem too, otherwise the glass industry is going to be in decline for a long time. Those are real issues that are very challenging, because it took us 60 years to reach where we are, and we have to solve whole other problems within 10 years. Accelerating that technology in that period of time will be very difficult.

9. But as far as the structural properties of glass are concerned do you think there is room for improvement? We have talked a lot about thin glass. That is an area we have been involved in for 3-4 years now. Finding applications for that has been difficult, but probably because thin glass needs to be combined with other elements, e.g. composites. We need to

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find applications where we can use much thinner glass, which is lighter and more sustainable and therefore more transparent. You can combine it with other technologies, and since it comes from an electronics background, we should be embracing the fact that you can get 4K television which is basically on LCD glass, and yet we can barely put a frit on a window! So we have to somehow figure out how that technology moves from one to the other, in the built environment and how we can embrace that. There are a lot of great ideas. So I think that there is innovation in the material in terms of thin glass, and how you combine it with other materials. With the glass itself â&#x20AC;&#x201C; less so, probably. There could be, but it is an economic challenge to reinvent the way the glass is made, because it needs such a huge infrastructure that exists in float lines all around the world. Changing the recipe and changing the process is more expensive than inconceivable. But you know, it would be a good idea to do it. We are still making glass in the same way we did 60 years ago which seems to me fairly unprogressive. Relatively speaking, we managed to progress many things we can do with the raw material but we have not managed to progress the raw material itself. That is a challenge for the material scientists of the world to solve.

10. How do climate conditions affect glass structures, for example in climates with cold winters and warm summers? Is the extreme change of temperatures a problem for glass structures? Yes, I think there is a number of problems. The glass itself is pretty stable at most temperatures where human beings live. So the substrate is fine. It tends

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to be the materials we laminate with that have the problem, the polymers that bond the glass together. They have relatively limited temperature range. In fact, they are really problematic even within the temperature range we live in as human beings. So most of them at around 50oC change dramatically, and below 10oC quite a bit. While the ambient temperature is never more than 40oC in the desert, obviously the heat that the glass absorbs heats it up, so its temperature can reach 80-90oC, which actually is quite problematic for the interlayers that we use. Even now that is a problem, and there is not a solution to that yet. The highest bound interlayers are around 50-60oC, and the current polymer formulas do not seem to be changing that dramatically. Thankfully, that is not that extreme when you are using glass, but it is a challenge. In terms of physically responding to different climates it is again a question of how you are detailing it, and not using certain types of materials when you are in that type of scenario. There may not be an answer

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when you need to make a laminated roof panel in the middle of the Sahara Desert. Particularly if you are doing things on the glass, like putting coatings on it to keep the sun out and digitally printing it to reduce the solar gain. All you are then doing is actually creating something that is absorbing more heat. So the glass becomes hotter and hotter, so there are points when it just does not work. But you know there is not an awful lot of demand for glass structures in the Sahara Desert or the Arctic. Most of them are in areas in which we live, and thankfully we live in areas which do not have particularly extreme climates, from a temperature standpoint. From a wind and hurricane standpoint, the question is more relevant today, because the codes are changing. We are finding that we are designing structures to withstand higher forces, so as to respond within the codes, to what we see as natural progression in heavier storms, more wind etc. So again it is a mathematical issue. We end up with the glass getting thicker the connections getting bigger, as

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you have to absorb more forces.

11. You have been working with some very demanding architectural designs. To what extend do you believe that the collaboration between architects and structural engineers can be productive and feasible? I think it is beyond that. I think any architecture that does not have a productive collaboration with an engineer is not fulfilling its potential for good design. My whole working life has been fundamentally based on my relationship with architects. My understanding for architecture, my appreciation of architecture, my complete drive to make the ambitions of an architect work, and at the same time bringing pragmatism to that design, bringing economic feasibility to that design, bringing creative

“It is not about doing math or being asked how big is this beam, or how big is this duct, or how big is this pipe. It is about asking the question, about why you need the beam, or why you need the duct, or why you need the pipe. ” 38

innovation to that design. That is what I believe structural engineers and architects should be doing together. Let’s not forget that structural engineers and disciplines outside of architecture were once all within architecture. So to ask the question of it being feasible, you need to look back to the beginning and see that actually you were the same person. You still should be the same person, and if you are not then you are not doing your job properly.

12. And a last question for us, young engineers. What would your advice be for young engineers in their beginning of their career? Take up banking! (Laughs) Actually some consider that change already! Too many of you do that, which is a shame! It is far less creative. Perhaps in the good old days of banking when you could do anything, it was more creative. Nowadays it is not a creative field, there is too much legislation so it is not even interesting anymore. (Laughs) It is a very difficult question actually, because I employ a lot of young engineers. I think that is very important to keep your knowledge broad. If you are in the field of Civil and Structural Engineering, look outside of what you are doing to what other people are doing, and let those influences come into what you are doing. I have obviously been working for many years now, to look back, to look at myself even at that period of time, I think that my sight was too narrow. I did not fully understand in the beginning enough about architecture. That came later in my professional development, and it would have been

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better if it was earlier in my development. At the end of the day, a big part of a structural engineerâ&#x20AC;&#x2122;s job is to facilitate architecture, so you should understand architecture. If you are an architect, the converse is true. You should understand what your engineers are trying to bring to you earlier in the game. You can spend forever focusing on form and function and Rhino models, but I think it is quite of importance to have an appreciation of the wider role. For me, as an engineer, I think is really important to be very strong analytically. The most successful engineers that I work with come at least from a very strong analytical background. That is something that is a building block, which you can work on. The element of creativity is also really important. Doing what you can to be as strong as you can analytically, but remembering that you are an engineer and an engineer is about solving problems. It is not about doing math or being asked how big is this beam, or how big is this duct, or how big is this pipe. It is about asking the question, about why you need the beam, or why you need the duct, or why you need the pipe. You cannot get through life just by sizing things. That is not really what the game is about. Travel around the world, try to understand it. Understand how people do things in different parts of the world. I did that a lot. That benefited me hugely. I lived in Asia, I lived in America and I lived in Europe, and I worked in all those places, seeing how people engineer and solve things in different parts of the world. It brings you a much wider and diverse picture, to how you might go about doing things in your own little world. That helped me a lot.

Thank you for the advice and thank you for the interview also. 39

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M E X R E T E E X T R E ME By Job Schroën

In 2013 Ulrich Knaack and I started a Master 2 course called “Extreme”, about building in extreme climates. The course is about integral design. Integral design means that a design is not just an architectural or spatial idea, but a single design which deals with many aspects such as architecture, structure, climate, and so on. You could say that in Extreme we try to make architecture that works, especially from a technical point of view. Since September Extreme has started as an MSc1 course. It consists of a 12 ECTS part, which takes an extreme environment and a program as a starting point (e.g. a concert building in an earthquake zone), and a smaller part of 6 ECTS, which is a research course on a related subject. Both have the same objective, to forget about “Jellema” and learn from the problems, which the students encounter. What we really try to teach at Extreme however is that you shouldn’t think you could learn how to make architecture, making architecture is learning: at every project you will learn new insights. That is of course what Extreme, and probably most of the university, is about: obtaining an attitude of curiosity

and pleasure in finding things out. To me it is important for our students to get a thorough understanding for integral design, not just learn about the concept of integral design, instead they should experience what it means to work in this way. That is the main reason why we chose extreme climates as a subject: in an extreme situation you really need to understand what is going on and find proper solutions. I remember being in a meeting at our faculty, where one teacher pointed out there isn’t enough time to teach students everything relevant in architecture. I think he continued on the importance of knowledge on bricks and timber structures, but for me the eye opener was already there: I think it is quite clear we cannot train students in, for example, all materials, all building methods or all architectural vocabulary. What we do is show that if you want to build in a certain way, or with a certain material, or make a specific type of building, there is only one thing to do: dive into the subject and find out everything there is to know about it.

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Zi g g o D o me, A m s t e r d a m This is similar in the professional field, a project I very much enjoyed working on was Ziggo Dome, of which I was project architect at Benthem Crouwel. Ziggo Dome was the first building in the Netherlands which was intended to be a concert building for amplified music, with a large capacity, 17.000 visitors. All other concert buildings are either smaller (HMH can accommodate 5.500 people) or were intended for different use (Ahoy, Gelredome, ArenA). This meant there were many â&#x20AC;&#x2DC;extremeâ&#x20AC;&#x2122; problems to be solved, and nobody in the Netherlands had much experience. Figure 1 : Ziggo Dome, Amsterdam

One of many examples of the problem we ran into were the toilets in the Ziggo Dome. We found out that at some concerts there are, of course, 80% men, at others 80% women. At the same time we had both spatial and financial challenges, which is why I proposed to make flexible toilets: with a screen in three positions (fig.2) the ratio of male and female toilets can be altered, even during a concert (which happens quite often). In this way we only needed 500 toilets and urinals. We also made the toilets on the left of the building independent of the toilets on the right, so whatever happens, there will always be 250 toilets available.

Figure 2 : Toilets grid, Ziggo Dome, Amsterdam

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Extreme Forces

Figure 3 : Toilets, Ziggo Dome, Amsterdam

The acoustics of the Ziggo Dome were another challenge. For amplified music reverberation time is the key to good sounding performances. A reverberation time of about 1,5 to 2 seconds is considered very good, but opinions differ. The Heineken Music Hall is considered to have a ‘dry’ acoustic with a reverberation time of 1,1 seconds. The ArenA soccer stadium had a reverberation time of 9 seconds before measures were taken to improve this time. This longer time has to do

Figure 4 : Urinals, Ziggo Dome, Amsterdam

with the size of the concert hall. Basically you’d like to absorb sound (at the right place and at the right frequency) for which you need, of course, insulation. As a room gets bigger the walls and ceiling grow to the power of two, whereas the volume of the room grows to the power of three. You can imagine the amount of sound needed has something to do with the volume of the room, the insulation with the area of the walls and ceiling. As the ceiling is not a great place for insulation (the speakers are aimed at the audience) and also is not big enough, we opted for a new idea. We made the vertical parts of the balconies transparent for sound, so that sound, especially low frequencies can be absorbed behind the balconies. This made the Ziggo Dome’s reverberation time 1,8 seconds, very good for amplified music, but also it set the limit to what the size of a good hall can be.

Figure 5 : stands tribunes construction, Ziggo Dome, Amsterdam

You can learn more about the Ziggo Dome in this AT5 interview with Job on Youtube: https://youtu.be/3ugxZpRPcbo?list=FLGO7eMHOvmlSysFI8xR-AhQ

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Th e P a l e i sb u r g , t h e Ne t h e r la n ds Bent hem C r o uw el Ar chi t ect s Another good example of integrated design was the Paleisbrug, of which I was project architect at Benthem Crouwel as well, and for which we recently won the “Nationale Staalprijs”. For the Paleisbrug competition we had suggested to make an elevated park instead of a narrow and long pedestrian bridge. We won the competition and Piet Oudolf joined our team to make the landscape design. A big problem we encountered was that this was going to be both a park and infrastructure. You might have noticed that in winter, when we’ve had snow, there is no salt being used to melt snow in parks. This is no such option as many plants would not survive the salt, and it is not a big problem to have snow in parks, as they are not part of the main infrastructure. We solved this problem in our project by integrating floor heating in the bridge deck. We could connect the floor heating to an existing ground-source heat pump. In this way we could use the bridge in summer as a giant solar collector, which produces more heat than it needs in winter. The entire system uses some electricity for its heat pump, but otherwise is energy positive.

Figure 6

Figure 7

Of course this system is crucial to the design of a park-bridge in this way, it will however not be experienced by many people. For me it was extremely nice that the bridge got quite some good reviews, in both the Landscape and Architecture yearbooks. Figure 6-7 : The Paleisburg Figure 8 : floor heating system Figure 8

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The Sta i r c a s e

A last example of an integral design approach is a project which Iâ&#x20AC;&#x2122;m currently working on. The staircase of a new house is designed with the objective to make an elegant staircase within a limited space and budget. The design is a spiral staircase, in which the inner stringer is not a column, but a helix which is out of phase with the outer stringer. The inner stringer is a single ongoing helix, whereas the outer stringer has two horizontal parts for the flights at first and second floor. This is possible by making the steps of the staircase asymmetrical: the steps in the lower half are mirrored to the steps in the second part of the staircase. The staircase needed quite a lot of thought to make the architecture work: it is a geometric puzzle, has quite complex structural engineering and at the same time it should be relatively easy to build.

Figure 9: 3D printed model

Figure 10: construction phase

Figure 11: transportation phase

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Figure 12: installation in-place

Extreme Forces

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Job Schroën graduated at our faculty of Architecture in 2001. After graduation he worked for GBAU, Wessel de Jonge, Benthem Crouwel and Hubert-Jan Henket & Janneke Bierman. He worked on several museums: Stedelijk Museum in Amsterdam, Brabants Museum in ‘s-Hertogenbosch, Fries Museum in Leeuwarden and Anne Frank Museum in Amsterdam. Also he worked on several concert buildings: Metropool in Hengelo and Ziggo Dome in Amsterdam. He designed a bridge at Benthem Crouwel with Piet Oudolf in ‘s-Hertogenbosch. He started his own architecture firm “September architectuur” in 2013, working on projects as different as energy positive villa’s to giving children’s workshops at the Stedelijk Museum in Amsterdam. Job is a main mentor at the Architectural Engineering Studio and is coordinator of Extreme, an MSc2 course.

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Structural Transparency The Crystal Houses facade

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By Ir. Faidra Oikonomopoulou

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Located in the heart of Amsterdam, the Crystal Houses faĂ§ade, designed by MVRDV Architects, sets a great example of the structural potential of cast glass. The new facade is an accurate yet entirely transparent reproduction of the buildingâ&#x20AC;&#x2122;s original 19th century masonry elevation. Solid glass bricks reinterpret the standard brickwork and the typical architraves above the openings, even the traditional wooden frames of the openings are translated into massive cast glass elements. As the facade ascends, conventional clay bricks intermingle in between the glass ones to create a gradient transition to the normal brickwork on the top, residential floor. The end result is a building that stands out and at the same time blends naturally into the urban fabric of the historic street (fig. 1).

48 Figure 1: The Crystal Houses faĂ§ade in Amsterdam

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Based on the structure of the former masonry faรงade, the elevation of 10 by 12 meters employs more than 6500 solid glass bricks, each 210 mm thick and 65 mm high. Glass casting was the only solution for producing glass components of this cross-section. Each brick was manually cast obtaining every time a distinctive inner flow pattern as the liquid glass solidifies, revealing the hand-made process of the elements (fig.2).

Figure 2: The manual, individual casting of each brick gives them a distinctive inner flow pattern.

The desire of the architects to attain transparency at its purest did not allow the use of any visible supporting structure, rendering the choice of an entirely self-supporting glass block system necessary. Since this was a novel structural solution, the challenge of the materialization as well as of the fabrication techniques of the solid glass block wall were assigned to the Delft University of

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Technology and in specific to researchers Ir. Faidra Oikonomopoulou and Ir. Telesilla Bristogianni under the supervision of Prof. Rob Nijsse and Dr. Ir. Fred Veer. In principle, a glass masonry wall of the abovementioned dimensions is plausible thanks to the high compressive strength of glass and the 3-dimensional nature of the masonry wall that makes the construction buckling-resistant. Indeed, just one glass brick can carry the complete dead load of the faรงade! The lateral stability of the glass faรงade was further enhanced through its geometry. Four buttresses, formed towards the interior of the faรงade by interlocking bricks, result in a continuous relief of increased rigidity. To obtain an all glass structural system a colourless adhesive should be applied for bonding the bricks. The lack of standardized strength data and building guidelines for such an application of structural adhesives necessitated the research and testing on various different adhesives at the Glass and Transparency Lab at TU Delft, in order to find one that would fulfil both the visual and structural prerequisites. Actually the mechanical properties of the adhesive are equally critical to the ones of the glass blocks for the developed system, as it is their interaction as one structural unit that defines the structural capacity and properties of the glass masonry. The most favourable structural performance is when the adhesive and the glass blocks fully cooperate, allowing the masonry wall to function as one rigid unit against loading, resulting in a homogeneous load distribution.

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Most adhesive candidates were discarded already in the early stages of research due to their coloration, insufficient shear strength or too high flexibility. Eventually, visual prototypes and structural tests directed the research to a photo-curing family of clear adhesives especially designed for glass to glass bonding, with high shear stiffness and good long and short term compressive behaviour. Visually, the adhesive has a similar refraction index to glass and does not discolour when exposed to sunlight. Another important feature is its photo-catalytic curing which allows for fast construction: it takes less than a minute for the adhesive to cure under UV-radiation, acquire its full structural capacity and become moisture- and water- resistant. Series of 4-point bending tests on 1.2 m long glass beam specimens, each comprising 3 arrays

of glass bricks, proved the monolithic behaviour of the system when bonded by this adhesive. All specimens acted as one single rigid unit under loading by failing with a straight, clear-cut in the middle (fig.3). However, the structural tests also revealed that the chosen adhesive reaches its optimum (and desired) bond strength when applied in a layer of a mere 0.3 mm thickness. The low viscosity and effectively zero ideal thickness of the adhesive together with the inelastic nature of glass generated several implications concerning its homogeneous application that resulted in exceptionally strict allowable tolerances regarding not only the brickâ&#x20AC;&#x2122;s dimensions but also the overall faĂ§ade. Not only the size of each brick unit, but even each layer of the construction of the glass wall had to be confined within a tight dimensional precision of a quarter of a

Figure 3: The failure pattern of the glass beams tested under 4 point bending demonstrates the monolithic behaviour of the system under loading

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Figure 4: PURE® mould used for the application

Figure 5: The wall after the mechanical

of the adhesive on the final façade wall.

removal of a broken glass brick

millimeter. This demand of an unprecedented high level in accuracy and transparency in construction introduced various challenges during the engineering and construction of the Crystal Houses façade, calling for innovative solutions.

controlling the flow, spread and amount of the adhesive (fig.4).

The required +0.25 mm tolerance necessitated the _ post-processing of the manually cast glass units: during the cooling of the molten glass, natural, inevitable shrinkage occurs to all surfaces of the glass component. After the annealing of the bricks, this shrinkage was removed from the bonding surfaces by a CNC polishing machine to provide glass elements of the desired precision. A completely transparent wall bears yet another challenge: Any small defect in the adhesive layer, even an air bubble three meters above the ground, is entirely visible. To minimize inconsistencies in the glue layer, a special bonding technique for the uniform distribution of the glue was developed, utilizing specially designed PURE® moulds for

Given the central location of the Crystal Houses façade, the system’s endurance on presumable impacts by objects such as bottles, bricks and bicycles also had to be tested. A hard body impact and a vandalism test were performed on an experimental glass wall to simulate accidental as well as intentional impact by small objects. Although the glass wall was able to withstand the hard body impact test, the attack by a sledgehammer caused internal cracking to the aimed brick. This suggested that a rapid impact force causes only local damage, which does not transfer to the rest of the wall. The vandalism test highlighted the importance of developing a replacement method in case of damage. Such a method was developed by locally applying high temperature to weaken the adhesive until the damaged component can be mechanically removed (fig.5).

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After 18 months of research, the system had been developed and proved both structurally and visually and the construction started. The nature of the adhesive required the elevation of the glass faรงade inside a tent to provide protection against the sun radiation, dust and the weather elements. Six to ten highly skilled building crew were working daily for seven months on the elevation through a strictly controlled construction process. The extremely high level of accuracy and transparency required, generated many engineering challenges during the erection of the wall that demanded the daily presence of researchers Faidra Oikonomopoulou and Telesilla Bristogianni at the site as quality control engineers (fig.6).

Figure 6: The TU Delft researchers supervising on site as quality control engineers.

Together they controlled all 6500 bricks used in the construction and even built together with the crew the first 1.5 meter of the glass wall! As this construction is the first of its kind, new construction methods and tools had to be utilised: from high-tech lasers and laboratory UV-lamps, to slightly lower-tech Dutch full-fat milk, which proved to be an ideal liquid to function as a reflective surface for the levelling of the first layer of bricks in a precision of 0.25 mm over 12 m of length! At present, the Crystal Houses faรงade has been completed, illustrating the great potential of the developed adhesively bonded glass brick system as an answer to the quest of structural transparency and setting the foundation for novel architectural applications (fig.7).

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Figure 7: The effect of light in the Crystal Houses faรงade

Ir. Faidra Oikonomopoulou is a Lecturer and PhD Researcher at the Research Group of Structural Mechanics at the Faculty of Architecture, TU Delft. Her research focuses on innovative structural applications of glass and on the design of all-glass load-bearing structures and components. Ir. Faidra Oikonomopoulou has been involved in the study of the Crystal Houses faรงade from the initial stages of the project as the leading PhD researcher for the development of the novel glass brick wall. She assembled and tested several prototypes of wall fractions to explore its structural and visual performance and provided novel solutions to answer the challenges coming from the very high level of transparency and dimensional accuracy required. Together with fellow colleague Ir. Telesilla Bristogianni they supervised as quality control engineers the complete construction of the Crystal Houses faรงade on site and even constructed together with the builders the first 1.5 meter of the glass wall!

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Extreme Forces

Folded Glass Plate Structures

A deployable roof system By Alkistis Krousti

Introduction Folded plate structures have been the object of extensive research as far as their geometrical, structural and kinematic properties are concerned. These approaches however to their greatest extent focus on each one of those aspects separately and as a result there has been few efforts for an integral result, combining the structural and kinematic benefits of foldable structures for architectural applications. Since the introduction of new materials such as wood, composites and glass, there has not yet been a full exploration of the new potentials deriving from different material properties and innovative manufacturing techniques. The purpose of this master graduation project is to explore to which extent the kinematic qualities of folded geometries can be combined with the

structural benefits of glass plates and more specifically, how can these be applied in the case of a deployable glass roof system. In the scope of this project, a final architectural product has been developed for the specific needs of covering in an adjustable way the area of an outdoor swimming pool area. This project has followed a design by research methodology based on experimental testing and geometry evolution based on structural performance. The geometry development aspect, directly linked to the structural performance and the hinge connection development aspect were proceeded separately aswell as in parallel . The combination of the two outcomes is an integrated design that shows that it is feasible, within an experimental context, to efficiently apply folded plates geometries in a

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deployable roof roof system system (able (able to to cover cover aa span span of of deployable 20m).The Thestructural structuraland andkinematic kinematicperformance performanceof of 20m). deployable roof (able to cover a spanand of the product is is thesystem result of of constant feedback and the product the result constant feedback 20m). The structural and kinematic performance of development between between the the geometry geometry and and structural structural development the product isas the ofwhole constant feedback and performance, as farresult as the the whole structure and the performance, far as structure and the development between the geometry and structural plateconnections connectionsare areconcerned. concerned. plate performance, as far as the whole structure and the plate connections areexploration concerned. of Design Goal The The exploration of deployment deployment Design Goal possibilities of of glass glass folded folded plate plate structures structures in in possibilities Design Theproject exploration of deployment the scopeGoal of this this has been been focusing on on the scope of project has focusing possibilities of glass folded plate structures in developing systemcovering coveringan anopen openspace spacewhich which developing aasystem the scope of this project has been focusing on requires adaptability, adaptability, either either because because of of functional functional requires developing a system covering an open space which or climate climate requirements. requirements. In In this direction, direction, spaces spaces or requires adaptability, either this because of functional with high architectural standards and seasonal use with high architectural standards and seasonal use or climate requirements. In this direction, spaces were considered, added a relatively small span, in were considered, added a relatively small span, with high architectural standards and seasonal usein order for thestructure structure tobe be feasiblein inglass. glass. Sport order the to feasible Sport werefor considered, added a relatively small span, in facilities, and especially swimming pools provide an facilities, pools provide an order forand the especially structure toswimming be feasible in glass. Sport ideal example. Swimming, amongother othersports, sports,is isaa ideal example. Swimming, among facilities, and especially swimming pools provide an preferably outdoor activity,among also related related to leisure, leisure, preferably outdoor activity, also to ideal example. Swimming, other sports, is a however highly weather dependent. As result, however highly weather dependent. As result, preferably outdoor activity, also related toaaleisure, swimming poolshave have very discreteseasonal seasonal use, however pools highly weather dependent. As a result, swimming aavery discrete use, swimming pools have a very discrete seasonal use, most frequently combining outdoor and indoor indoor most frequently combining outdoor and most frequently outdoor indoor facilities. Moreovercombining swimmingpools poolsare areand considered facilities. Moreover swimming considered facilities. Moreover swimming pools are considered as leisure leisure centers, centers, besides besides training training areas, areas, which which as as leisure centers, besides training areas, which

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Case Olympic pool pool area area (50m (50mxx70m). 70m). Case study: Olympic Case study: Olympic pool area (50m x 70m).

meanshigh higharchitectural architecturalqualities qualitiesoften oftensought soughtfor, for, means

means high architectural aswell well asnatural naturallight. light.qualities often sought for, as as as well as natural light.

Themain mainarchitectural architecturalgoals goalsof ofthe theproposed proposedsystem system The

The main architectural goals of the proposed system are: are: are: 1. To create create aa temporary temporary climate-controlled climate-controlled 1. To 1.enclosure To create a outdoor temporary climate-controlled enclosure overan an outdoor sport facility,in inthis thiscase, case, over sport facility, enclosure overpool. an outdoor sport facility, in this case, swimming aaswimming pool. a swimming pool.

2. 2.

To create create aa structure structure allowing allowing view view to to the the To

2. To create a structure allowing view to the exterior and and natural natural lighting, lighting, providing providing as as much much exterior exterior and natural lighting, providing as much transparency as possible. transparency as possible. transparency as possible.

Forthe the next design development steps, the case For the next design development steps, For next design development steps, the the casecase study has been simplified to a foldable roof system study has been simplified to a foldable roof system study has been simplified to a foldable roof system based on planar geometry of rectangle boundary based aaplanar geometry aarectangle boundary based onon a planar geometry of aof rectangle boundary 70 x20 20 m. 70 70 x x20 m.m. Concept of design designboundaries boundariesfor for the boundaries for the Conceptdiagram diagram of the deployablesystem. system. deployable deployable system.

355

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ExtremeForces Forces Extreme a

hi S b θi

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a simple to more to complex ones. Starting and from ageometry simple geometry more complex ones. from a very simplified folding made out made of twoout plates Starting from a very simplified folding of under an angle, as seen in fig.3.16, and moving on to two plates under an angle, as seen in fig.3.16, and increase and add moreand parameters, moving onthe to complexity increase the complexity add moreit will eventually become possible to draw conclusions parameters, it will eventually become possible to on theconclusions behavior of on thethe system and the which draw behavior of way the in system this is affected by geometry parameters, such as the and the way in which this is affected by geometry pattern angle,such folding etc. angle, folding parameters, as angle, the pattern angle, etc. Different units and ways of applying these loads have been triedand in the finite well Different units ways ofelement applyingmodel, these as loads as different types of edge connection, trying to get have been tried in the finite element model, as well the most efficent simulation. Particular attention has as different types of edge connection, trying to get been paidefficent to the matter of safetyParticular measures.attention Because the most simulation. of the material’s brittle behavior and the sudden has been paid to the matter of safety measures. failure that it can present without prior warning, Because of the material’s brittle behavior and special regulations predicted for the sudden failure and that factors it can are present without glass structures and more specifically for roofs. prior warning, special regulations and factors are q Max stress l

1.60E+09

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θ=8

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θ=45

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θ=65

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RuMoer #63 PRINCIPLE STRESS STRESS S1 S1 PRINCIPLE

predicted for glass structures and more Based on the above equations and on specifically theoretical for roofs. constraints for folded plate structures, geometry Based the above andthe onspectrum theoretical the firston goal has beenequations to determine of geometry folded plate structures, the folding constraints angle, θi. Asfor shown by the results of first the first goal has been to determine the8ospectrum and 60o hand calculations , within the limits of of folding the folding θi. As shown results of angleangle, θi folded plates are by stillthe operating of firstprimarily hand calculations , within when the limits of 8o either as beam elements, the angle o and 60 ofsmaller, foldingor angle θi folded plates are still is getting as plate elements, when the operating eitherlarger. primarily as beam elements, when angle is getting the angle is getting smaller, or as plate elements, when the is getting Based onangle those first larger. hand-calculations and using the predefined design limit stresses and Based on those first hand-calculations and deformations different combinations of plate sizes the predefined design stresses and ausing and thicknesses t were tried, limit for the given span combinations plate sizes ldeformations = 20 m anddifferent considering the most of unfavorable o. a and thicknesses t were tried, for=the span deployment configuration, at θi 60given . First a l = 20 m and considering thegeometry most unfavorable grasshopper scipt defining the was used, deployment configuration, at θi =tool 60o.Karamba . First a in combination with the parametric grasshopper scipt defining the geometry was used, for the draft comparison of different settings, while in combination with the finite element method viaparametric TNO Diana tool was Karamba used for for the draft comparison of different the more accurate structural analysis.settings, while finite element method via TNO Diana was used for Hinge connection development the more accurate structural analysis. Hinge connection development The application of the thermoplastic polypropylene PURE composite , developped by DWI Holding Theand application of the thermoplastic polypropylene B.V the exploratiion of its potential as hinged PURE connection composite , developped DWI one Holding B.V plate materia hasby been of the and the exploratiion of itssince potential hinged plate research sub-questions the as begining, and connection materia has one ofdeveopment. the research thus a starting point of thebeen connection sub-questions the begining, thus a The design aimssince regarding the hinge and connection starting have pointbeen of determined the connection principle as: deveopment. aimsdesign-maximum regarding the hinge connection •The design Discrete transparency have been determined •principle Tolerance in both x and y as: direction Discrete design-maximum •• Waterproofing (restriction oftransparency gaps) Tolerance both x and y direction •• Repair workinfacilitated • Waterproofing (restriction of gaps)

DEFORMED SHAPE SHAPE DEFORMED

PRINCIPLE STRESS STRESS S1 S1 at at TOP TOP PRINCIPLE

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Thefinal finalmock-up mock-up,,,using usingdiscs discs cut cut out out of floar glass, 20mm The glass, 20mm 20mm The final mock-up using discs diameter and 3mm 3mm thickness. thickness. diameter thickness.

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surfaces on the roof outcome systems, as a waythe to combine both All in all, shows potential of kinematc and structural performance aspects. This applying the folding principle of planar “origami” result can apply to different surfaces onbe roofextrapolated systems, as atoway to combine both building systems and materials, besides structural kinematc and structural performance aspects. This glass. hasbe been shown that the is result Itcan extrapolated to proposed apply to design different feasiblein terms of structural performance, material building systems and materials, besides structural behavior andbeen connection principle. In terms of the glass. It has shown that the proposed design is innovative hinge connection, it appears that the feasiblein terms of structural performance, material material, the specific connection principle is behavior under and connection principle. In terms of the ainnovative feasible and highly promising innovation. hinge connection, it appears that the material, under the specific connection principle is a feasible and highly promising innovation.

strain/time 5sec 14 12 10 8

6 4 2 0 9.6 1960.4 3887.7 5812.3 7725.8 9642.5 11566.3 13500.9 15418.9 17330.1 19236.6 21141.3 23058.2 24970.6 26890.4 28816.5 30740.2 32650.8 34561.8 36484.1 38394.3

Since the PUREwork compositehas • Repair facilitated not previously been use in construction applications, there were not satisfactory litterature data to be This Since the PURE compositehas notconsidered. previously been meant that all material and connection properties use in construction applications, there were not need to be thoroughly investigated. In the scope satisfactory litterature data to be considered. This of this reasearch, a series of tests, meant that all material and connectionconcerning properties both and connection priciple need material to be thoroughly investigated. In properties the scope have been conducted in the lab, mainly fatigue, of this reasearch, a series of tests, concerning and pull-out tests. Additionally to those, a set of both material and connection priciple properties finite element analyses was run to determine the have been conducted in the lab, mainly fatigue, maximum bearing loads of the connection and and pull-out tests. Additionally to those, a setthe of proper dimensioning for the application. finite element analyses wasparticular run to determine the maximum bearing loads of the connection and the Kinematics The detailing of the mechanical system proper dimensioning for the particular application. of deployment enabling this roof system has been aKinematics very essential complex part of the realization Theand detailing of the mechanical system of this project. The main goal is to ensure that of deployment enabling this roof system has been movement is powered in the given direction, the a very essential and complex part of the realization detailing of the rail guarantees that the boundary of this project. The main goal is to ensure that conditions remain pinned assumed in the movement is powered in theasgiven direction, structural model and tolerances can be taken on at detailing of the rail guarantees that the boundary least one side to take the induced deflection. conditions remain pinned as assumed in the All in all, model the outcome shows can thebepotential structural and tolerances taken on of at applying the folding principle of planar “origami” least one side to take the induced deflection.

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5500-strain (mm)

Extreme Forces Extreme Forces

HIDDEN RAILS

STEEL ROD Φ 30mm for rotation around x-axis

MOTOR HIDDEN RAILS 5 horse 10m/sec

STEELBEARINGS ROD Φ 30mm BALL for rotation around x-axis

TRANSPORTER MOTOR uses rail 10m/sec clamps as parking 5 horse brakes TRANSPORTER uses rail clamps as parking brakes

BALL BEARINGS

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The Patching of Built Ornamental Heritage using Digital Fabrication By Ali Sarmad K han The research project aimed to explore the role of LIDAR Technology and Digital Fabrication techniques in the field of architectural conservation, particularly for the patching of ornamental heritage. Experiments were performed using various professional 3D scanning, digital fabrication, and traditional mold making techniques for the transference of geometry. Another aspect of the research was to explore the use of various mesh generation and manipulation methods. The information could then be used by conservationists to aid in conservation efforts when traditional methods are either not sufficient or not feasible, thereby exploring the role of the â&#x20AC;&#x2DC;Neo-craftspersonâ&#x20AC;&#x2122; in the digital age. To gather subjective insight on the topic, professional conservationists were also interviewed and all opinions are recorded. Test Cases The restoration target was a Belgian Blue Limestone column fragment found in the basement of BK City. The case had mechanical damage on one corner, and exhibited symmetricity (to be used as reference geometry).

First Test Sample - 10g White Pigment

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Digitization

Interpolation of missing geometry

The 3d scanning for the project was aided by a Delft based company called Delfttech. It was determined that for the kind of geometry to be scanned, it would be ideal to use the Phase Difference based Zoller + Frรถhlich Imager 5010C scanner. The scans were carried out in an improvised setup prepared inside a room in the Architectural Engineering and Technology faculty. These scans were then stitched via the scanner firmware into one cohesive point cloud with reference markers providing a fixed coordinate system for the stitching.

For the interpolation of the missing geometry, the Boolean approach was used. In polygonal modeling, Booleans operations generally subtract, intersect, merge or split overlapping meshes by detecting geometry that lies within or outside the overlapping sections. In this instance, the missing geometry was generated via a subtractive boolean operation that removes the overlapping geometry and just leaves the missing components.

1 Identification

Lasercanning with Z&F Imager 5010C Phase Shift Scanner

Alignment

4 Mirroring OR Boolean Operations

Imported Point Cloud

Rotation

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SPN: 1

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SPN: 4

SPN: 15

SPN: 20

Mesh Processing

Interpolation

The Poisson Surface Reconstruction method was used to generate the meshes. This method interpolates surfaces using a best fit method via the Poisson algorithm.

The Boolean operations were primarily performed on Geomagic Wrap, a proprietary software for processing point clouds. The processed mesh was mirrored, aligned (using identifiable features as a reference) to achieve maximum overlap, self-intersecting and nonmanifold surfaces were removed using the Mesh Doctor tool and the remaining surfaces were removed manually to leave the missing fragment with the complementary fracture surface.

Green hues indicate the centralized displacement of the mesh. It can be seen that at a Samples Per Node value of 20, the mesh is the smoothest and displacement starts to affect the fracture surface, which would have an effect on the fitting of the manufactured fragment.

The average displacement remained quite unpredictable however. A value of 15 was selected as a compromise between noise and detail and was exported in the PLY format for further processing.

The mesh was then further processed using a Geomagic Sculpt to refine the details and ensuring a perfect fit on the existing column geometry.

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Final Production Since the use of FDM (Fused Deposition Modeling) 3D printing technology was selected as the primary mode of production, the print had to be manufactured in two parts to fit in the limited build volume of the Ultimaker 2+ Extended printer. A tolerance of 0.3 mm was used for the cylindrical inserts. A higher value was used so that small adjustments could be made if necessary during the glueing process. An extruded platform was modeled on top of the fragment to create a pouring cavity during the production of the mold.

Mold Reinforcement

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Extruded platform for mold

Top Fragment

Cylindrical Holes = 6.3 mm

Cylindrical Inserts Height =15 mm

= 6 mm

Bottom Fragment

An enclosing box was modeled to save material while pouring the silicone shell. The box was milled out of MDF and would be clamped together during the manufacturing process. The box consisted of two pieces with simplified cavities that conformed to the basic shape of the fragment to be manufactured but with an offset of 2 cm. This would essentially be the thickness of the second silicone shell.

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19 6.6

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Transference of Geometry 1 2 3

1. â&#x20AC;&#x2DC;Patternâ&#x20AC;&#x2122; fastened using clay, application of release agent and three layers of brush-on silicone.

2. Application of release agent on inner surface of mold reinforcement.

4. The MDF mold reinforcement is released and the polymer pattern is manually extracted from the silicone shell, it is reassembled and a release agent is applied to the inner surface.

3. Second layer of silicone is poured inside the cavity of the mold reinforcement and left to cure.

5. The casting material is poured (cement, plaster etc.), vibrated to minimize trapped bubbles, left to cure and eventually extracted.

Each sample was casted in two sessions, with 600g cement and 300g water. The first sample was mixed with no aggregate or sand and 10g of white pigment, the second sample used more pigment (20g) and 1350g (1 bag) of fine aggregate and sand. After pouring halfway, each sample was vibrated for 30 seconds for compaction, filled till the end marker and compacted again.

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On many occasions it may be a necessity to use Digital Fabrication as an aid to the restoration process in conjunction with other techniques rather than as the primary technique. On its own, Digital Fabrication is not an effective tool for the patching of geometry, it has to be used in conjunction with other technologies like laser scanning (LIDAR) or photogrammetry. It also has to be evaluated whether the damage to an ornament is more than skin deep and whether the use of Digital Fabrication can exacerbate the existing damage. Factors that influence the selection of Digital Fabrication technology can include the complexity of the geometry of the ornament (which can determine whether the use of DF is required or not or which technology would be more applicable), the material of the ornament, whether reversibility is a priority, whether the available traditional techniques are better alternatives, if authenticity is a priority or whether applicable traditional techniques have been lost. Once a technology has been selected, there can be various parameters that affect the end result. These include the level of noise in the scans, the flexibility provided by the selected software packages, the resolution of the selected manufacturing technology, whether there is hybridization with other technologies and the scale of the fragment to be manufactured.

Second Test Sample - 20g White Pigment

One factor that does not play a very significant role however is economics, since a majority of the cost of such restorations comes down to labor costs and both traditional and new techniques require the use of labor in one form or another.

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E V E N T S O V E R V I E W OCTATUBE EXCURSION

On the 17th of March, BouT and several Building Technology + Architecture students went for an excursion to glass-specialist company Octatube which is famous for constructing remarkable glass facades, such as in Markthal (Rotterdam) and the new entrance of the Van Gogh Museum in Amsterdam. After an inspiring lecture, we got the opportunity to walk around the factory floor. There they test the facade mock-ups and the latest innovations. Biggest thanks to Joeri Bijster, Barbara van Gelder, and Kuno Jacobs for having us! Also thanks and good luck to Carlyn who just graduated at Octatube on the subject of ultra-thin glass!

SPRING BBQ

In early May we were able to enjoy the weather and have the first BBQ of 2016 and the first one organised by the new board. Drinks, food and sharing Bucky Lab stories are a good recipe for fun!

SPOORZONE EXCURSION

On the 11th of May, BouT visited the construction site of Delftâ&#x20AC;&#x2122;s new Railway Station. We could see how the tunnels were being constructed beneath all the monumental houses and canals â&#x20AC;&#x201C; which makes Netherlands a unique country. There, you could witness the archaeological items that were uncovered, from musical instrument to cannonballs. The excavation also exposed the walls and gates which were made to defend Delft centuries ago.

praktijkvereniging Bout

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DEBUT

Debut.event 2016, BouT’s very own company-case day, has taken place last Wednesday and it has been a great success! Thanks to all who participated, your input was very valuable. If you have not done so: please send your case presentation to info@debut-event.nl and we will make sure to forward it to the companies. The pictures of the event will be online this week and see you all next year!

BUILDING with BAMBOO

A collaboration between Students 4 Sustainability, Bamboo Social and BouT resulted in a event worth repeating! We - together with BambuSocial and S4S - thank you very much for joining Building with Bamboo. It is definitely not often that you get a chance to build bamboo construction which was used by the whole campus in the Bouwpub. All the pictures are up in our Facebook page and website and don’t forget to contribute by sending your ideas to BambuSocial. Maybe you’ll be the next bamboo expert!

SUMMERSCHOOL POLAND

Design and Build Summer School of Architecture has dazzled with a successful closure in Poland. Together with BouT, BuckyLab’s inimitable work enthusiasm took place at The Wroclaw University of Science and Technology to design shelters for refugees. Four extraordinarily designed shelters even caught the attention of the Polish Press and were published in several newspapers.

SUMMER BBQ

In September the new academic year required a second edition of the BBQ to give (new) BT students a chance to meet and greet. Continuing the BouT BBQ tradition (which used to include the board actually having to build their own BBQ).